Metallic-filament lamp.



0. BIRNBAUM.

METALLIC PILAMENT LAMP.

APPLIOATI-OK nun nov. a. 1910.

1,009,129. v Patented N0v.21, 1911.

. 2/ 2- I M a F122 Q 7 O2 2 3 WITNESSES: U U U INVENTGR OTTILIEiBIRNBAUM. CF VIENNA AUSTRIA-HUNGARY. ASSIGNOR TO WESTINGHOUSE LAMPCOMPANY. A CORPORATION OF PENNSYLVANIA.

IvIETALLIC-FILAMENT LAME.

Specification of Letters Patent.

Patented Nov. 21, 1911.

Application filed November 3. 1910. Serial X0. 591,298.

'10 111! wrlmm it may; concern:

lie it known that l, ()rrtmr. Bnzxmmn a mtqeet of the llmperor offuistria-llun- Portions. There will of course be some eon- 2-.r v. and aresident of Vienna. Austrianprov mrut R lating to MetaHie-FilamentLamps, of which the following is :1 speeitieaso great as when the endportions themselves lion.

Yi 'le an iu'iproverl lamp of this kind in fr m lngr-oz'uing -"erheat'l.

ln lll tfll filament troops as usually made. the rrw-z -seetior1 of theleading-in wires and inter ;.--lial;e supports to whirl: the filam ntsare attarhed is sutlieienttv great to preventia-rua-lv s. N that thros+ss-y-ti n of the leading-in wires and intermediate supp rts 7 musthe made sullieiently great to allow for this tar-tor also in order thatthey shall not he orerlwated.

there is a teud uev f r the \.-u-uu:n in the lamp hull; to heroineimpaired. and for the :drrkened owing to disinii-gr-stion of theu'iaterlal of which the leadi l? gin wires and supports are made. 1.:\\'t" .'t!'. leading-1n \vue of great r russr--':tiou are employeddillieulties oreur when tuning the same into the glass stemof the lampand in fuel. this operation in such a ease can only be carried out bythe exercise i of peeial precautions.

This applies par tir-ularly in the'ease of lamps ltlttn lttl to take acurrent exceeding one ampere.

The object of the present inv ntion is achieved hy diminishing, thePlOIl-lt'ilfill of heat due to the passage .of current through thoseportions of the filamentsavhieh are near to the l ading-iii wires andintermediate supports. The :nnount of heat produced by the current inthese portions em; he (liminished by rudu zing the resie'tanmr, forinstaneu by increasing the effective -.l'u$S-5i"-- tinn of the ndportions f the filament by brow-hing llH. sam while the g neration f hat in the t'lll portions min be eliminated almost entirel by short- .-ir..-uiting the end Hungary, have invented a new and useful I:

This invention Ptlflt(' to metalfilament e m-Erie lamps and has for itsobject to prothe leading-in wires and intermediate sup- --h th l hlliif-lz'. viws and internn-diate ll the l ading-in wires and 1intermediate supports are heated i-:-:.':essivel v and a loop 4 ofermduetin; material conpertioas of adjacent filaments so that almost thewhole of the current flows from one filament to the next withouttraversing the end duet ion of heat. through these end portions, but thetlttlfllt on the leading-in wires and intermediate supports Wlllobviously not be are also heated by the Whole of the current. In botheases, however, the cross-section of ports can he made much smaller thanhas hitherto been possible.

In the accompanyingdrawings.Figures 1 and 2 represent diagrammaticallytwo arrangements of the filaments in aerordanee with the presentinvention. The filaments are of course in fact arranged around the glassstem of the lamp, but for the purpose of simplicity are here showndeveloped in one plane.

referring to Fig. 1 the end portions of the filament 1 which areconnected to the leading-in wires 2 and intermediatesupports 3 areprovided with hranehes which form parallel paths for the Luz-rent. Tnthis nartieular ease the filament is provided near each end with. a kinkor bend,

Meets this kink to the loading-in wires .2 or intermediate supports 3.these loops may conveniently eoDSist of the same material thefilamentitself. The blllflt'lllllfl' of the filament can he carried outin any suitable manner in which the resis'anee of the end portions ofthe filament is redneed so that less heat is generated and ronsequentlyless of the filaments or the intermediate supports with the result. thatthese end portions are not. heated to the temperature they would attainif they were traversed by the whole of the current. It, will he nhviousthat this looping together of the. filaments can only take plaee asregards the intermediate supports, while for the leading-in wires the.cross-section of the end portions of the filament Conner-ted theretomust be increased by providing loops or hranehes as described above. Theend portions of filaments adjaeent to one :Huz-tllt'l' ean ohvioustv becaused to toneh over their entire length, in order to short-eirenitthese end portions.

The kink or bend in the filament to whieh the loops areattaelu-d or hmeans of wlrieh the filaments are looped together. is eonvenientlyprodueed after the filaments have been made. in the ease of duetilefilaments they can readily he bent by an\' snitahle means, but in theease of sintered filaments the filaments are heated to a temperature atwhieh they heeome pliahle. whereupon the kink is made and the filamentallowed to 0001-.

1. in a metal filament eleetrie lamp, the combination with theleading-in wires and intermediate supports, of filaments pi-{wided witha kink near their points of: atta hment to said leading-in wires andintermediat supports, and loops of conducting material passing aroundsaid kink and attaehed to the leading-in wires and intermediate supportsrespectively.

2. in a metal filament electric lamp the combination with the leading-inwires and intermediate supports of filaments attached to said leading-inwires and intermediate supports, the end portions of said filamentsheing short-cireuited at a point near their to said leading-in wires andintermediate supports. the filaments which are attached to saidintermediate supports being provided with a kink in their end portionsand interlooped at said kink.

I). in a metal filament" eleetrio lamp the etnnhinaiion with theheading-in wires and intermediate sii pi iorts 0t filaments attaehed tosaid leadiugzfin wires and intermediate supports, said fiflaments beingprovided with a kink in their end portions, the filaments whieh areattaehed to the intermediate supports heir; inter-looped at said kinkand the filaments whieh are attaehed to theleading' in wires havingloops of COI\(ltt(tlI1f "i!i:\- terial in eontaetwith-the kink andattaehed to the leading-in wires.

in testimon} whereof I have hereunto subscribed my name this 27th day of()etoher 191.0.

OTTI LI E BIRNR A I i) I.

"itnesses SUSAN Lisuicinza, ADA MARIA BERGER.

